PARIS, France (AFP) — As global concerns about mpox continue to rise, straightforward questions about the disease’s danger and the differences between its variants remain complex and nuanced.
On August 16, 2024, the World Health Organization (WHO) declared an international health emergency due to the rapid spread of mpox. Initially identified in humans around 1970 in the Democratic Republic of Congo (DRC), the disease remained confined to a few African countries for decades, displaying a mortality rate ranging from one to ten percent among infected individuals.
However, global uncertainty about mpox has grown since 2022, when the virus started spreading to Western countries, reporting significantly lower mortality rates of approximately 0.2 percent. This discrepancy in mortality rates is influenced by various factors, including access to medical care, underlying health conditions, and the specific mpox variant involved.
Quality of Medical Care
Antoine Gessain, a virologist specializing in mpox, emphasizes that the danger posed by mpox is closely tied to the quality of basic healthcare available. In Western countries, swift and appropriate medical treatment contributes to lower mortality rates. In contrast, the current outbreak’s mortality rate in the DRC is around 3.6 percent, primarily because the disease is confined to regions with limited medical resources.
Vulnerable Populations
The mortality rate also varies with the characteristics of the affected population. In the DRC, over 500 children, often malnourished, have died out of more than 15,000 cases. Conversely, the 2022-23 epidemic in the DRC saw around 200 deaths out of 100,000 cases, mostly adults with weakened immune systems due to HIV infection.
Transmission Modes
Differences in how the disease is transmitted add further complexity. The 2022-23 epidemic saw significant transmission through sexual activity among homosexual or bisexual men. Although mpox transmission modes can vary, the latest outbreaks demonstrate the importance of considering how and among whom the virus spreads.
Variants and Clades
The mpox virus has different clades, or families, complicating the understanding of its health risks and transmission patterns. The 2022-23 epidemic was attributed to Clade 2 mpox, which is prevalent in western Africa but also present in South Africa. In contrast, the current deadly outbreak in the DRC is caused by Clade 1 mpox, primarily found in central Africa. Adding to the complexity is a sub-variant known as 1b, a derivative of Clade 1, which has recently emerged and shows distinct characteristics.
There has been media confusion, with some outlets erroneously labeling variant 1b as more dangerous than other mpox forms. Dutch virologist Marion Koopmans has cautioned against these claims due to the lack of concrete evidence. While it is established that Clade 1 is generally associated with more severe disease compared to Clade 2, researchers urge caution in interpreting these findings.
Need for Further Research
The urgency to establish accurate facts about mpox variants intensifies as Clade 1 was detected outside Africa for the first time, appearing in Sweden in mid-July. Virologists like Gessain underscore the difficulty in comparing different clades due to varying contexts and at-risk populations. Comparing malnourished children to HIV-positive adults highlights the complexity of drawing conclusive parallels.
Conclusion
In conclusion, the complexity in understanding mpox underlines the necessity for comprehensive and context-sensitive research. As the disease continues to affect diverse populations worldwide, coordinated global efforts become even more critical to managing and mitigating its impact.
For now, public health officials, researchers, and the global community remain vigilant, looking to unravel the complex story of mpox to ensure better preparedness and response to future outbreaks.
